JP6638411B2 - Swing joint device - Google Patents

Description

  The present invention relates to a rocking joint device that makes a periodic rocking motion.

  As an example of a device that controls a joint that makes a periodic rocking motion, Patent Literature 1, for example, discloses a one-legged walking assist device that assists human walking. This one-legged walking support device is mounted on a waist-mounted portion mounted on the side of the user's waist, a thigh link portion disposed on the side of the user's thigh, and mounted on the user's lower leg. And a lower leg link portion. The upper part of the thigh link portion is connected to the waist mounting portion so as to be swingable in the front-rear direction of the user, and applies an assist torque to the thigh link portion between the waist mounting portion and the thigh link portion. A torque generating device for performing the operation is provided. Walking assist is performed by applying the assist torque of the torque generating device to the thigh link portion. The torque generating device is configured to be capable of applying an assist torque to the thigh link portion by the action of the compression spring, the cam and the cam follower, and the magnitude of the assist torque is determined by a predetermined compression amount of the compression spring. (Spring force of the compression spring). The compression amount of the compression spring is set manually using a tool.

JP 2013-236741 A

  In the above-described one-legged walking support device, since the compression amount of the compression spring is manually set using a tool, it is not possible to change the compression amount according to the swing angle of the thigh link portion during walking. Have difficulty. For this reason, it is difficult to change the assist torque in real time according to the swing angle of the thigh link portion, and to perform walking assist with high efficiency.

  Therefore, a swing joint device 300 having the configuration shown in FIG. 11 is conceivable. The oscillating joint device 300 includes an oscillating motion part 310, a speed reducer 320, a mainspring 330, and a drive motor 340. The oscillating unit 310 is mounted, for example, on the side of the thigh 350 of the user 400 and performs reciprocating oscillating motion according to the walking of the user 400. The energy of the oscillating motion of the oscillating motion unit 310 is temporarily input to the mainspring spring 330 via the speed reducer 320, and the energy is re-emitted from the mainspring spring 330 to the oscillating motion unit 310 to allow the user 400 to walk. Assist. The speed reducer 320 amplifies the torque output from the mainspring 330 and inputs the amplified torque to the swinging motion unit 310. The drive motor 340 rotationally displaces one end of the mainspring spring 330 with respect to the other end in accordance with the swing angle of the swinging motion section 310, so that the apparent rigidity of the mainspring spring 330 viewed from the swinging motion section 310 (spring spring). Change the spring force). Therefore, the torque output from the mainspring 330 to the rocking motion section 310 is adjusted in real time according to the rocking angle of the rocking motion section 310.

  In the oscillating joint device 300, the speed reducer 320, the mainspring 330, and the drive motor 340 are coaxially arranged toward the side of the waist 360 of the user 400. This coaxial arrangement simplifies the connection configuration between the members. However, when the reduction gear 320, the mainspring spring 330, and the drive motor 340 are coaxially arranged, the swing joint device 300 becomes thicker toward the side of the waist of the user 400. Therefore, the upper limb (not shown) of the user 400 may hit the swing joint device 300, which is not preferable.

  An object of the present invention is a rocking joint device that accumulates energy corresponding to a rocking angle of a rocking motion unit that reciprocates rocking motion in an elastic body and discharges the stored energy to the rocking motion unit, and Another object of the present invention is to reduce the thickness of the rocking joint device in a rocking joint device that can adjust the apparent rigidity of the elastic body viewed from the rocking motion unit according to the rocking angle of the rocking motion unit.

  In order to solve the above problems, the present invention employs the following means.

  According to a first aspect of the present invention, there is provided an energy storage mode which is connected to a reciprocating rocking moving body and stores energy in an elastic body by the movement of the moving body, and a moving body which releases energy stored in the elastic body. A swing joint device that alternately repeats an energy release mode that supports the motion of the rocker, a rocking motion portion that rocks around a rocking center that is the center of the reciprocating rocking motion, and a rocking motion of the rocking motion portion. An elastic body that accumulates energy or emits energy according to the moving angle, a stiffness varying unit that has a drive motor and varies the apparent rigidity of the elastic body as viewed from the oscillating motion unit, and an oscillating motion unit Angle detection means for detecting the swing angle of the object and stiffness variable means controlled in accordance with the swing angle detected by the angle detection means to adjust the apparent rigidity of the elastic body as viewed from the swinging motion part. Control means and swing A deceleration that is interposed between the moving part and the elastic body, converts the input rotation amount input from one of the swinging movement part and the elastic body into an output rotation amount based on a predetermined conversion ratio, and outputs the output rotation amount to the other. Machine. At least two of the reduction gear, the elastic body, and the drive motor are arranged in parallel without being arranged so that they are all coaxial.

  A second invention of the present invention is the swing joint device according to the first invention, wherein the elastic body is a spring. Then, the apparent rigidity of the elastic body viewed from the swinging motion part is an apparent spring constant of the mainspring viewed from the swinging motion part.

  A third invention of the present invention is the swing joint device according to the second invention, wherein the speed reducer has two input / output shafts that rotate coaxially and is input to one of the input / output shafts. The input rotation amount is converted into an output rotation amount based on the conversion ratio and output from the other input / output shaft. The rigidity variable means is connected to one end of the mainspring and has a first power transmission means when the drive motor is arranged in parallel with the mainspring. The other end of the mainspring and one input / output shaft of the speed reducer are connected directly or via second power transmission means. The other input / output shaft of the speed reducer and the swinging motion part are connected directly or via a third power transmission means. The conversion ratio of the reduction gear is set so that the rotation amount of the other input / output shaft on the side of the swinging motion part is smaller than the rotation amount of one input / output shaft on the other end side of the mainspring. Have been.

  A fourth invention of the present invention is the swing joint device according to the third invention, wherein the stiffness varying means includes a stiffness adjusting member for rotating one end of the mainspring about a spring central axis which is the center axis of the mainspring spring. And a drive motor for rotating the rigidity adjusting member coaxially with the mainspring via the first power transmission means. The first power transmission means is connected to an output shaft of the drive motor and rotates coaxially with the output shaft. The first rigidity variable pulley has a larger diameter than the first rigidity variable pulley, and has a first rigidity variable. A second stiffness variable pulley, which is connected to the pulley by a belt, is connected to the stiffness adjusting member, and rotates the stiffness adjusting member coaxially with the mainspring.

  A fifth invention of the present invention is the swing joint device according to the fourth invention, wherein the rigidity adjusting member is configured to rotate coaxially with the mainspring spring, and to rotate integrally with the adjusting unit main body. An outer end connection portion and a plurality of diameter expansion regulating portions. The outer end connecting portion extends in parallel with the center axis of the spring and is connected to an end on the outer peripheral side of the mainspring, which is one end of the mainspring. Each of the diameter expansion restricting portions extends parallel to the spring center axis around the outer periphery of the mainspring.

  A sixth invention of the present invention is the swing joint device according to the fifth invention, wherein each of the diameter expansion restricting portions is disposed on the opposite side of the spring center axis from the outer end connection portion. I have.

  A seventh invention of the present invention is the swing joint device according to the fifth or sixth invention, wherein each of the diameter expansion restricting portions is formed in a shaft shape, and the respective diameter expansion restriction. Rollers rotatable around the axis of each diameter expansion restricting portion are mounted on the portions.

  In the configuration of the first invention, the control means changes the apparent rigidity of the elastic body as viewed from the swinging motion section in accordance with the swing angle of the swinging motion section, whereby the swinging motion from the elastic body is changed. The energy output to the unit is adjusted in real time, and the reciprocating swing motion of the moving body is assisted with high efficiency. Further, in the configuration of the first invention, since at least two of the speed reducer, the elastic body, and the drive motor are arranged in parallel, bulkiness of the member in one direction is suppressed, and the swing joint device is thin. Be transformed into

  In the configuration of the second invention, the elastic body is a spring. As is well known, the mainspring reduces the diameter or expands in accordance with the rotational displacement of the one end with respect to the other end in the forward and reverse directions, and accumulates elastic energy. Therefore, in the oscillating joint device, unlike the case of using a spring that can store elastic energy only by a displacement operation in one direction of extension like a coil spring, deceleration is caused by the reciprocating oscillating motion of the oscillating motion part. The elastic energy can be stored in response to both forward and reverse rotation operations input from the machine. As described above, the mainspring stores elastic energy in accordance with the rotational displacement. Therefore, in the swing joint device, unlike the case where a spring that stores elastic energy according to a linear motion displacement, such as a coil spring, is used, the linear motion is changed to the rotary motion in the connection mechanism between the mainspring and the speed reducer. No mechanism is required, and the connection mechanism can be easily configured. Therefore, the swing joint device is downsized.

  In the configuration of the third aspect of the invention, since the speed reducer is interposed between the oscillating motion part and the mainspring spring, the torque output by the mainspring spring is amplified and input to the oscillating motion part. Accordingly, a relatively small spring having a small spring constant can be employed, and a load applied to a member supporting the spring when the spring is rotationally displaced is reduced. Therefore, the spring can be downsized, the number of members for supporting the spring can be reduced, and the swing joint device can be downsized.

  In the configuration of the fourth invention, since the diameter of the second rigid pulley is larger than the diameter of the first variable rigidity pulley, the torque output from the drive motor is amplified and transmitted to the rigidity adjusting member and input to the mainspring. Is done. Therefore, the torque of the drive motor can be reduced, the drive motor can be downsized, and the current consumption of the drive motor can be reduced.

  In the configuration of the fifth invention, the rigidity adjusting section has a plurality of diameter expansion restricting sections extending around the outer periphery of the mainspring parallel to the spring center axis. Each of the diameter expansion restricting portions restricts the spread of the mainspring by contacting the outer periphery of the mainspring when the mainspring is in the expanded state. Therefore, the deformation of the mainspring is kept within a predetermined range. Therefore, in the swing joint device, the space to be secured for the deformation of the mainspring can be set small, and the size of the swing joint device is reduced.

  In the configuration of the sixth aspect, each of the diameter expansion restricting portions is disposed on the opposite side of the outer end connecting portion with respect to the center axis of the spring. When the mainspring is in a diameter-expanded state, a portion opposite to the end on the outer peripheral side with respect to the center axis of the spring spreads radially outward. Therefore, since each diameter expansion restricting portion is disposed on the opposite side to the outer end connecting portion with respect to the spring center axis, the radial expansion of the mainspring is restricted.

  In the configuration according to the seventh aspect of the invention, rollers are mounted around each of the diameter expansion restricting portions. Accordingly, each of the diameter expansion regulating portions regulates the spread of the mainspring while contacting the outer periphery of the mainspring with the roller and smoothly guiding the outer periphery in the circumferential direction.

It is the perspective view showing the state where the assist device was worn by the user. It is the perspective view which looked at the variable rigidity unit from the side of the outward face of the base member. It is the perspective view which looked at the variable rigidity unit from the inward side of the base member. It is the perspective view showing the variable rigidity unit in the disassembled state. It is a perspective view of a rigidity adjustment member. It is a front view of a rigidity adjustment member. It is a front view of an output link. It is a front view of a mainspring in a free state. It is a front view of the mainspring showing the state which rotated the inner end from the free state. It is the front view of the mainspring showing the state which rotated the inner end and the outer end relatively from the free state. It is a front view of the conventional rocking joint device.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The assist device 1 shown in FIG. 1 is an example of a swing joint device. The assist device 1 assists an operation such as walking or walking of a person. The X direction, the Y direction, and the Z direction shown in each figure correspond to the front direction, the left direction, and the upward direction of the user U wearing the assist device 1.

  The assist device 1 includes a control box 3 and a variable stiffness unit 10 as shown in FIG. The control box 3 is mounted on a first mounting device 5 mounted around the waist U1 of the user U. The control box 3 is arranged at the center of the waist U1 of the user U. The control box 3 contains a control means 9 for controlling a drive motor 52, which will be described later, and a battery (not shown) for supplying power to the control means 9 and the drive motor 52.

  As shown in FIG. 1, the variable stiffness unit 10 is attached to a second attachment 6 attached around the waist U1 of the user U. The variable stiffness unit 10 is disposed on the left leg side of the user U, on the side of the waist U1 of the user U. The variable stiffness unit 10 has a plate-shaped base member 11. The base member 11 has one surface facing the user U, and the other surface facing the user U. Hereinafter, in the base member 11, the surface facing the user U is referred to as an inward surface 11a (see FIG. 3), and the surface facing the user U outward is referred to as an outward surface 11b (see FIGS. 1 and 2). The base member 11 has a mounting projection 19 on an upper part thereof. The mounting projection 19 has a through hole 19a (see FIG. 4) penetrated in the front-rear direction. The second attachment 6 is inserted into the through hole 19a. In addition, both surfaces 11a and 11b of the base member 11 are covered with a cover (not shown).

  As shown in FIG. 1, the variable stiffness unit 10 has an output link 20 (oscillating motion unit). The output link 20 extends downward from the base member 11 and is arranged along the side of the thigh U2 (exercise body) of the user U. The distal end of the output link 20 is a user mounting portion 20a that is folded upward. The user mounting portion 20a sandwiches the third mounting device 7 mounted around the thigh U2 of the user U. Thus, the output link 20 is attached to the thigh U2 of the user U. The output link 20 reciprocates in the front-rear direction of the user U about a pivot center axis P1 (see FIG. 4) described later in accordance with the reciprocating pivoting motion of the thigh U2.

  As shown in FIGS. 2 and 4, the base member 11 includes the output link 20, the speed reducer 30, the input / output power transmission means 40 (second power transmission means), the mainspring 100 (elastic body), and the rigidity variable means 50. And so on. The rigidity varying unit 50 includes a drive motor 52, a rigidity adjusting power transmitting unit 53 (first power transmitting unit), and a rigidity adjusting member 80. The reduction gear 30, the mainspring spring 100, and the drive motor 52 are arranged in parallel without being arranged coaxially. That is, the two input / output shafts 32 and 34 of the speed reducer 30, the spring center axis P <b> 2 which is the center axis of the winding of the mainspring 100, and the motor output shaft 52 a which is the output shaft of the drive motor 52 are parallel to each other. In a relationship. Both the input / output shafts 32 and 34, the spring center axis P2, and the motor output shaft 52a extend in the thickness direction of the base member 11 (lateral to the user). Note that the speed reducer 30 is located below the drive motor 52. The mainspring 100 is located behind the speed reducer 30 and the drive motor 52.

  As shown in FIGS. 3 and 4, the output link 20 has a connection portion 20b at an end opposite to the attachment portion 20a. The connection part 20b is arranged on the inward surface 11a side of the base member 11. More specifically, the connection portion 20b is disposed in the link accommodating recess 13 in which the inward surface 11a is recessed in the thickness direction. The connection portion 20b is directly connected to a first input / output shaft 32 (see below) of the speed reducer 30 by, for example, a bolt B, and cannot rotate relative to the first input / output shaft 32. The output link 20 reciprocally swings (rotates) with the first input / output shaft 32 about the axis of the first input / output shaft 32. In FIG. 4, the unified reference symbol P1 is assigned to the axis of the first input / output shaft 32 and the center axis of the swing of the output link 20. The swing center axis P1 extends to the side of the user's waist at a position corresponding to the user's hip joint. The bolt B1 connects the output link 20 to the first input / output shaft 32 on the swing center axis P1. The rotating part of the encoder 130 (angle detecting means) is attached to the bolt B1, and the fixed part of the encoder 130 is attached to the base member 11 (not shown). The encoder 130 detects the swing angle of the output link.

  As shown in FIG. 4, the speed reducer 30 includes a first input / output shaft 32 and a second input / output shaft 34 held coaxially, and a rectangular fixed portion formed around the first input / output shaft 32. 36. The fixing part 36 is fixed to the reduction gear housing part 14 provided on the base member 11. The reduction gear accommodating portion 14 is a through hole in which the base member 11 penetrates in a thickness direction in a shape corresponding to the fixing portion 36, and is provided at a position facing the link accommodating concave portion 13. The first input / output shaft 32 is disposed over both surfaces 11 a and 11 b of the base member 11, and the second input / output shaft 34 is disposed on the outward surface 11 b of the base member 11.

  The speed reducer 30 converts the input rotation amount input to one of the input / output shafts 32 and 34 into an output rotation amount based on a predetermined conversion ratio n, and outputs the output rotation amount from the other. The first input / output shaft 32 rotates at a reduced speed with respect to the second input / output shaft 34 based on the conversion ratio n. The second input / output shaft rotates n (n> 1) for one rotation of the first input / output shaft 32. The first input / output shaft 32 is connected to the output link 20 as described above. The second input / output shaft 34 is connected to the inner end 102 (see below) of the mainspring 100 via the input / output power transmission means 40, as described later. Accordingly, the speed reducer 30 is interposed between the output link 20 and the mainspring 100 and outputs the input rotation amount input from one of the output link 20 and the inner end 102 of the mainspring 100 based on the conversion ratio n. Convert to quantity and output to the other.

  As shown in FIGS. 2 and 4, the input / output side power transmission means 40 includes a speed reducer side pulley 42, a spring side pulley 44, and a belt 46 connecting both pulleys. The diameters of both pulleys 42 and 44 are the same. The pulleys 42 and 44 are arranged on the side of the base member 11 on the outward surface 11b. The speed reducer-side pulley 42 is attached to the second input / output shaft 34 so as not to rotate relatively, and rotates coaxially with the second input / output shaft 34.

  As shown in FIGS. 2 and 4, the spring-side pulley 44 is provided so as to face the mainspring 100, and is provided on the side opposite to the base member 11 with respect to the mainspring 100. A support shaft 110 extends through the axis of the spring-side pulley 44. The support shaft 110 is held coaxially with the spring center axis P2 by a rigidity adjusting member 80 described later. The spring-side pulley 44 is rotatably supported by the support shaft 110 coaxially with the spring center axis P2. The spring-side pulley 44 has a shaft-shaped inner end support portion 44 a on a surface facing the mainspring spring 100. The inner end support portion 44 a extends toward the mainspring spring 100 at a position radially away from the axis of the spring-side pulley 44. The inner end support portion 44a is fitted into the inner end 102 of the mainspring 100, and rotates the inner end 102 about the spring central axis P2 (see FIGS. 8 and 9).

  As shown in FIGS. 2 and 4, the mainspring 100 is disposed on the outer surface 11 b of the base member 11. The mainspring 100 is a spiral spring formed from a leaf spring. The inner end 102 (the inner peripheral end) and the outer end 104 (the outer peripheral end) of the mainspring 100 are each wound into a hole penetrating in the direction of the spring center axis P2. As described above, the inner end supporting portion 44a of the spring-side pulley 44 is fitted into the inner end 102. An outer end connection portion 92b (see below) of the rigidity adjusting member 80 is fitted into the outer end 104. Since the inner end 102 and the outer end 104 are supported, the spring central axis P2 of the mainspring 100 is held at a constant position. The above-mentioned support shaft 110 is not in contact with the mainspring 100.

  The mainspring 100 has a reduced diameter state in which the inner end 102 and the outer end 104 are relatively rotated in opposite directions about the spring center axis P2 from the free state shown in FIG. Then, it is deformed from the free state to the radially expanded state (see FIGS. 9 and 10) that expands radially outward, and stores elastic energy. Note that no elastic energy is stored in the mainspring 100 in the free state. The inner end 102 rotates according to the swing motion of the output link 20. The outer end 104 rotates according to rotation of a motor output shaft 52a described later. The motor output shaft 52a is connected to the outer end 104 via a rigidity adjusting power transmission means 53 and a rigidity adjusting member 80 described later. When the outer end 104 is rotated with respect to the inner end 102, the apparent rigidity (spring force of the mainspring) of the mainspring 100 viewed from the output link 20 is changed. The apparent rigidity of the mainspring 100 viewed from the output link 20 is the apparent spring constant of the mainspring 100 viewed from the output link 20. The rotation of the mainspring 100 will be described later in detail with reference to FIGS.

  As shown in FIGS. 2 and 4, the rigidity adjusting member 80 is disposed on the side of the base member 11 with respect to the mainspring 100. The rigidity adjusting member 80 has an adjusting portion main body 82, and a connecting overhang portion 92 and a regulating overhang portion 94 provided integrally with the adjusting portion main body 82. The adjusting portion main body 82 includes a large cylindrical portion 84 and a small cylindrical portion 86 provided in a stepped shape, and an adjusting disk portion 90 provided coaxially with the two cylindrical portions 84 and 86 and continuous with the small cylindrical portion 86. And The large column portion 84 is disposed in the adjustment member housing 16 provided on the base member 11. The adjustment member housing portion 16 is a circular through hole through which the base member 11 penetrates in the thickness direction. For example, a slide bearing 70 is fixed to the adjustment member housing 16. The sliding bearing 70 rotatably supports the large cylindrical portion 84. The large cylindrical portion 84 cannot withdraw from the slide bearing 70 in the axial direction. The small column portion 86 is arranged so as to protrude from the base member 11 toward the outward surface 11b. The adjustment disk portion 90 faces the mainspring spring 100. Note that a support shaft 110 is penetrated through the axis of the adjustment unit main body 82. The adjustment unit main body 82 holds the support shaft 110 coaxially with the spring center axis P2. The adjustment unit main body 82 rotates around the support shaft 110 coaxially with the spring center axis P2. The connecting overhang 92 and the regulating overhang 94 described later rotate integrally with the adjustment unit main body 82.

  As shown in FIG. 5, the adjustment disk portion 90 has a connection protrusion 92 and a regulating protrusion 94 that protrude from the outer peripheral surface thereof. The regulating overhangs 94 are provided at three places. Each of the restricting overhangs 94 will be separately described as a first restricting overhang 94A, a second restricting overhang 94B, and a third restricting overhang 94C. The configuration of each regulating projection 94A, 94B, 94C is the same. As shown in FIG. 6, each of the restricting overhangs 94A, 94B, 94C is provided on the opposite side of the connecting overhang 92 with respect to the axis P3 of the rigidity adjusting member 80. More specifically, each of the regulating protrusions 94A, 94B, 94C sandwiches a virtual straight line W perpendicular to the axis P3 of the rigidity adjusting member 80 and perpendicular to the direction in which the connecting protrusion 92 extends. And is provided on the side opposite to the connection overhang portion 92. The second restricting overhang 94B has a symmetrical positional relationship with the connecting overhang 92. The first regulating overhang 94A and the third regulating overhang 94C are provided, for example, at positions 60 degrees apart in the circumferential direction from the second regulating overhang 94B. Note that the axis P3 of the rigidity adjusting member 80 matches the spring center axis P2.

  As shown in FIG. 5, the connection overhang portion 92 has a connection extension portion 92a and an outer end connection portion 92b. The connecting extension 92 a protrudes radially from the outer peripheral surface of the adjustment disk 90. The outer end connecting portion 92b is a shaft portion protruding from the connecting extension portion 92a toward the spring 100, and extends in parallel with the spring center axis P2. The outer end connecting portion 92b is fitted into the outer end 104 of the mainspring 100, and rotates the outer end 104 around the spring center axis P2 (see FIGS. 9 and 10).

  As shown in FIG. 5, the restricting overhang portion 94 has a restricting extension portion 96 and a diameter expansion restricting portion 98. The regulating extension 96 projects radially from the outer peripheral surface of the adjustment disk part 90. The tip of the regulating extension 96 is located radially outward of the outer peripheral surface of the mainspring spring 100. The diameter expansion restricting portion 98 is a shaft portion protruding from the distal end of the restricting extension portion 96 toward the mainspring 100, and extends in parallel with the spring center axis P2. The diameter expansion regulating section 98 is arranged around the outer circumference of the mainspring 100. As shown in FIG. 10, the diameter expansion restricting portion 98 contacts the outer peripheral surface of the mainspring 100 in the expanded state, and functions to restrict the radial expansion of the mainspring 100. In addition, a roller R that is rotatable around the axis of the diameter expansion regulating unit 98 is attached to the diameter expansion regulating unit 98. The roller R smoothly guides the outer peripheral surface of the mainspring 100 in the expanded state in the circumferential direction.

  The drive motor 52 is fixed to the motor housing 18 provided on the base member 11, as shown in FIG. The motor accommodating portion 18 is a through hole in which the base member 11 penetrates in a thickness direction in a shape corresponding to the drive motor 52. The motor output shaft 52a protrudes toward the inward surface 11a of the base member 11. The motor output shaft 52a rotates in both forward and reverse directions. The rotation of the motor output shaft 52a is controlled by the control means 9. The rotation of the motor output shaft 52a drives the rigidity adjusting member 80 to rotate through the rigidity adjusting power transmission means 53 described later, and rotates the outer end 104 of the mainspring 100. An encoder (not shown) is attached to the drive motor 52.

  As shown in FIGS. 3 and 4, the rigidity adjusting power transmission means 53 includes a first rigidity variable pulley 54, a second rigidity variable pulley 56, and a belt 58 connecting the two rigidity variable pulleys 54, 56. The first variable stiffness pulley 54 is arranged on the inward surface 11 a of the base member 11 and faces the drive motor 52. The first rigidity variable pulley 54 is attached to the motor output shaft 52a in a state where it cannot rotate relatively, and rotates coaxially with the motor output shaft 52a.

  The second variable stiffness pulley 56 is disposed on the inward surface 11 a of the base member 11 and faces the stiffness adjusting member 80. The second rigidity variable pulley 56 has a support shaft 110 penetrated through its axis. The second variable stiffness pulley 56 is coaxially and rotatably supported by the rigidity adjusting member 80 by the support shaft 110. The second stiffness variable pulley 56 has a shaft-shaped connecting portion 56 a on the surface facing the stiffness adjusting member 80. The connecting portion 56a extends toward the rigidity adjusting member 80 at a position radially away from the axis of the second rigidity variable pulley 56. The connection portion 56a is fitted in a connection hole 84a provided in the large cylindrical portion 84 of the rigidity adjusting member 80. The connecting portion 56a rotates the rigidity adjusting member 80 around the support shaft 110.

  The second variable stiffness pulley 56 has a larger diameter than the first variable stiffness pulley 54. Therefore, the torque of the drive motor 52 is amplified and transmitted to the rigidity adjusting member 80 to be input to the mainspring 100. Therefore, the torque of the drive motor 52 may be small, the drive motor 52 can be downsized, and the current consumption of the drive motor 52 can be suppressed.

  The operation of the assist device 1 will be described. The reciprocating swinging motion of the output link 20 accompanying the walking of the user U is input to the mainspring spring 100 via the speed reducer 30 and the input / output power transmission means 40, and rotates the inner end 102 of the mainspring 100. This rotation will be described later with reference to FIGS. When the inner end 102 rotates, elastic energy corresponding to the swing angle of the output link 20 is accumulated in the mainspring 100. After that, the mainspring 100 rotates in the return direction so as to eliminate the rotational displacement of the inner end 102, thereby discharging the elastic energy accumulated therein toward the output link 20. The rotation of the mainspring 100 in the return direction is output to the output link 20 via the speed reducer 30 and the input / output power transmission means 40, and swings the output link 20. This swing assists the walking of the user U (the swing motion of the thigh U2 of the user U). As described above, in the assist device 1, the energy storage mode in which the elastic energy is stored in the mainspring spring 100 in response to the reciprocating swinging motion of the thigh U2 of the user U, and the elastic energy stored in the mainspring spring 100 is released to release the user U And the energy release mode that supports the reciprocating swing motion of the thigh U2 is alternately repeated. The control means 9 changes the apparent rigidity of the mainspring 100 viewed from the output link 20 in real time according to the swing angle of the output link 20. That is, the control means 9 rotates the motor output shaft 52a according to the swing angle of the output link 20 detected by the encoder 130. The rotation of the motor output shaft 52 a drives the rigidity adjusting member 80 via the rigidity adjusting power transmission means 53 to rotate the outer end 104 of the mainspring 100. As a result, the apparent rigidity of the mainspring 100 viewed from the output link 20 is changed. The rotation of the outer end 104 will be described later with reference to FIGS. The control means 9 changes the apparent rigidity of the mainspring spring 100 so that the user's own driving energy required for the reciprocating swinging movement of the thigh U2 of the user U is always minimized.

  The state of the rotational displacement of the mainspring 100 caused by the reciprocating swing motion of the output link 20 will be described. FIG. 7 shows how the output link 20 reciprocates. When the output link 20 is at the swing reference position shown by the solid line in FIG. 7, the mainspring spring 100 is in the free state shown in FIG. A reference line FF shown in FIG. 8 is a virtual straight line passing through the spring center axis P2 and the inner end 102, and indicates a reference position of the inner end 102. The reference line FF is a virtual straight line passing through the spring center axis P2 and the outer end 104, and indicates a reference position of the outer end 104. 8 to 10 schematically show only the diameter expansion restricting portion 98 and the outer end connecting portion 92b with respect to the rigidity adjusting member 80.

  The dotted line in FIG. 7 indicates a state in which the output link 20 has rocked from the rocking reference position in the clockwise direction (forward) by the rocking angle θ. In response to the swing of the output link 20, the inner end 102 of the mainspring 100 rotates clockwise from the reference position by a rotation angle n · θ from the reference position, as shown in FIG. As described above, n is the conversion ratio of the speed reducer 30. In FIG. 9, the drive motor 52 is not driven, and the outer end 104 is at the reference position. In the state shown in FIG. 9, a torque corresponding to the rotation angle n · θ acts on the inner end 102 in the counterclockwise direction. This torque swings the output link 20 counterclockwise (rearward) to assist the user in walking. When the inner end 102 of the mainspring spring 100 rotates counterclockwise in response to the swing of the output link 20, a clockwise torque acts on the inner end 102, and the output link 20 moves clockwise (forward). ) Rocked.

  FIG. 10 shows a state in which the drive motor 52 is driven to rotate the outer end 104 by a rotation angle θ1 in the counterclockwise direction from the reference position with respect to the state shown in FIG. In the state shown in FIG. 10, a torque equivalent to the sum of the rotation angle n · θ and the rotation angle θ1 acts on the inner end 102 in the counterclockwise direction. This torque is output to the output link 20 to assist the user in walking. In the state shown in FIG. 10, the outer end 104 is rotationally displaced with respect to the inner end 102, so that the apparent rigidity seen from the output link 20 is changed from the state shown in FIG. Therefore, in the state shown in FIG. 10, the elastic energy stored in the mainspring spring 100 is different from the state shown in FIG. When the outer end 104 is rotated clockwise from the reference position by the rotation angle θ1 with respect to the state shown in FIG. 9, the inner end 102 is obtained by subtracting the rotation angle θ1 from the rotation angle n · θ. Of torque works.

  As shown in FIG. 10, each diameter expansion restricting portion 98 contacts the outer peripheral surface of the mainspring 100 in the expanded state to restrict the mainspring 100 from spreading radially outward. Therefore, the deformation of the mainspring 100 is kept within a predetermined range. Therefore, in the rigidity variable unit 10, the space secured for the deformation of the mainspring spring 100 can be set small. Therefore, the rigidity variable unit 10 is reduced in size.

  As shown in FIG. 10, each of the diameter expansion restricting portions 98 is disposed on the opposite side of the outer end connecting portion 92b with respect to the spring center axis P2. As shown in FIG. 10, when the mainspring spring 100 is in the expanded state, a portion opposite to the outer end 104 across the spring center axis P2 expands radially outward. Therefore, since each diameter expansion restricting portion 98 is disposed on the opposite side of the outer end connecting portion 92b with respect to the spring center axis P2, the radial expansion of the mainspring spring 100 is surely restricted. .

  A roller R is mounted on each of the diameter expansion regulating sections 98. Accordingly, each of the diameter expansion regulating portions 98 regulates the spread of the mainspring 100 while contacting the outer peripheral surface of the mainspring 100 with the roller R and smoothly guiding the outer peripheral surface in the circumferential direction.

  The assist device 1 is configured as described above. In the above-described configuration, the control means 9 changes the apparent rigidity of the mainspring 100 viewed from the output link 20 in real time according to the swing angle of the output link 20, thereby outputting the output from the mainspring 100 to the output link 20. The energy to be applied is adjusted in real time, and the reciprocating rocking motion of the thigh U2 of the user U is assisted with high efficiency.

  In the above configuration, the speed reducer 30, the mainspring spring 100, and the drive motor 52 are arranged in parallel with the base member 11 arranged facing the side of the waist U1 of the user U (see FIG. 1). Therefore, the bulk of the member directed to the side of the user U's waist U1 is suppressed, and the rigidity variable unit 10 is reduced in thickness from the user U's waist U1 to the side.

  In the above configuration, the mainspring 100 is employed as the elastic body. The mainspring 100 stores elastic energy by reducing or expanding its diameter in accordance with the rotational displacement of the inner end 102 with respect to the outer end 104 in both the forward and reverse directions. Therefore, in the variable stiffness unit 10, unlike the case of using a spring such as a coil spring that can store elastic energy only by a displacement operation in one direction of the extension direction, the speed reducer is associated with the reciprocating swing motion of the output link 20. The elastic energy can be stored in response to the forward and reverse rotation operations input from the input unit 30. As described above, the mainspring 100 accumulates elastic energy in accordance with the rotational displacement. Therefore, in the variable stiffness unit 10, unlike a case where a spring that stores elastic energy in accordance with a linear motion displacement such as a coil spring is used, a linear operation is changed to a rotational operation in a connection mechanism between the mainspring 100 and the speed reducer 30. There is no need to change the mechanism, and the connection mechanism can be easily constituted by the reduction gear pulley 42, the spring pulley 44, and the belt 46. Therefore, the rigidity variable unit 10 is reduced in size.

  In the above configuration, since the speed reducer 30 is interposed between the output link 20 and the mainspring 100, the torque output from the mainspring 100 is amplified and input to the output link 20. Therefore, a relatively small mainspring 100 having a small spring constant can be employed, and the load applied to the member supporting the mainspring 100 when the mainspring 100 rotates is reduced. Therefore, the mainspring 100 can be reduced in size, the number of members supporting the mainspring 100 can be reduced, and the rigidity variable unit 10 can be reduced in size.

  Although the embodiments for carrying out the present invention have been described with reference to the drawings, the present invention is not limited to the structure, configuration, appearance, shape, and the like described in the above embodiments. Various changes, additions, and deletions can be made without changing the gist of the present invention.

  The reduction gear 30, the mainspring spring 100, and the drive motor 52 may be configured such that only two of these three are arranged in parallel. For example, the reduction gear 30 and the mainspring spring 100 may be arranged coaxially, and the drive motor 52 may be arranged in parallel with the reduction gear 30 and the mainspring spring 100. In this case, the input / output side power transmission means 40 is eliminated, and the reduction gear 30 and the mainspring spring 100 can be directly connected.

  The drive motor 52 and the mainspring 100 may be arranged coaxially, and the speed reducer 30 may be arranged in parallel with the drive motor 52 and the mainspring 100. In this case, the rigidity adjusting power transmission means 53 is eliminated. The drive motor 52 and the mainspring 100 are connected via a rigidity adjusting member 80.

  The drive motor 52 and the speed reducer 30 may be arranged coaxially, and only the mainspring 100 may be arranged in parallel with the drive motor 52 and the speed reducer 30. Note that the speed reducer 30 and the output link 20 may be arranged in parallel, and the speed reducer 30 and the output link 20 may be connected not directly but via an appropriate power transmission means (third power transmission means). . In this case, the two input / output shafts 32 and 34 of the speed reducer 30 and the swing center axis of the output link 20 have a parallel positional relationship.

  As long as each member constituting the assist device 1 functions in the same manner as in the above-described embodiment, the structure, configuration, appearance, shape, and the like can be freely changed.

  The assist device may be arranged and used on the right leg side of the user U. The configuration of the assist device in this case is symmetric with respect to the configuration shown in the above embodiment. The assist device may be mounted on each of the left and right legs.

  The elastic body is not limited to the mainspring 100, but may be any elastic body that can alternately repeat the above-described energy storage mode and energy release mode.

  The number of the diameter expansion restricting portions 98 is not limited to three, and may be any number. The arrangement of the diameter expansion restricting portion 98 may be on the opposite side to the outer end connecting portion 92b with respect to the virtual straight line W (spring center axis P2) shown in FIG. 6, and is limited to the arrangement shown in the above embodiment. Not something.

  The swing joint device of the present invention is not limited to the assist device 1 described above, and may be any device that controls a joint that makes a periodic swing motion.

1 Assist device (oscillating joint device)
9 control means 20 output link (oscillating motion part)
30 speed reducer 32 first input / output shaft 34 second input / output shaft 40 input / output side power transmission means (second power transmission means)
50 Stiffness varying means 52 Drive motor 52a Motor output shaft 53 Stiffness adjusting power transmission means (first power transmission means)
54 First stiffness variable pulley 56 Second stiffness variable pulley 80 Rigidity adjusting member 82 Adjusting portion main body 92b Outer end connecting portion 98 Diameter expansion restricting portion 100 Winding spring (elastic body)
102 inner end 104 outer end 130 encoder (angle detection means)
n Conversion ratio P2 Spring center axis R Roller

Claims (6)

An energy storage mode connected to a reciprocating rocking moving body to store energy in the elastic body by the movement of the moving body, and assisting the movement of the moving body by releasing the energy stored in the elastic body; An energy release mode, wherein the swing joint device alternately repeats
An oscillating motion portion that oscillates around an oscillating center that is the center of the reciprocating oscillating motion;
The elastic body that stores the energy or releases the energy according to the swing angle of the swing motion unit,
A stiffness varying means having a drive motor and varying the apparent stiffness of the elastic body as viewed from the swinging motion section;
Angle detection means for detecting the swing angle,
Control means for controlling the rigidity varying means in accordance with the swing angle detected by the angle detection means, and adjusting the apparent rigidity of the elastic body as viewed from the swinging motion part;
Interposed between the oscillating motion unit and the elastic body, converts an input rotation amount input from one of the oscillating motion unit and the elastic body into an output rotation amount based on a predetermined conversion ratio. And a speed reducer for outputting to the other side,
Three of the drive motor and the reduction gear and the elastic body, at least two are arranged in parallel without everything is arranged so as to be coaxial,
The reducer has two input / output shafts that rotate coaxially, and converts the input rotation amount input to one of the input / output shafts into the output rotation amount based on the conversion ratio, and converts the input rotation amount to the other. Output from the input / output axis,
The stiffness changing unit has a first power transmission unit that connects one end of the elastic body and the drive motor,
The other end of the elastic body and one of the input / output shafts of the speed reducer are connected directly or via second power transmission means,
The other input / output shaft of the speed reducer and the swinging motion unit are connected directly or via a third power transmission means,
The conversion ratio of the speed reducer is a rotation amount of the other input / output shaft on the side of the oscillating motion portion with respect to a rotation amount of one input / output shaft on the other end side of the elastic body. Is set to decrease,
The control means rotates the drive motor in accordance with the swing angle detected by the angle detection means, and rotates one end of the elastic body from a reference position via the first power transmission means. Adjusting the apparent rigidity of the elastic body as viewed from the swinging motion section,
Swing joint device. The oscillating joint device according to claim 1 ,
The rigidity changing means has a rigidity adjusting member for rotating one end of the elastic member to the spring center axis around a central axis of the elastic body,
The drive motor drives the rigidity adjustment member to rotate around the spring center axis via the first power transmission means,
The first power transmission means,
A first rigidity variable pulley connected to an output shaft of the drive motor and rotating coaxially with the output shaft;
The larger diameter than the first rigid variable pulley, and said together are first being rigid variable pulleys and a belt connection is connected with the rigid adjusting member, and the rigidity adjusting member around the spring center axis A second rigidity variable pulley that rotates the
Swing joint device. The oscillating joint device according to claim 2 ,
The rigidity adjusting member has an adjusting portion main body that rotates coaxially with the spring center axis, an outer end connecting portion that rotates integrally with the adjusting portion main body, and a plurality of diameter expansion regulating portions,
The outer end connecting portion is connected to the outer peripheral side of the end portion of the elastic body wherein a first end of the elastic member with extends parallel to the spring center axis,
Each of the diameter expansion restricting portions extends in parallel with the spring center axis around the outer periphery of the elastic body .
Swing joint device. The swing joint device according to claim 3 ,
Each of the diameter expansion restricting portions is disposed on a side opposite to the outer end connecting portion with respect to the spring center axis.
Swing joint device. The oscillating joint device according to claim 3 or 4 , wherein
Each of the diameter expansion regulating portions is configured in a shaft shape,
A roller rotatable around the axis of each of the diameter-increasing restrictors is mounted on each of the diameter-increasing restrictors.
Swing joint device. The oscillating joint device according to any one of claims 1 to 5 , wherein
The elastic body is a mainspring,
The apparent rigidity of the elastic body as viewed from the oscillating portion is an apparent spring constant of the mainspring as viewed from the oscillating portion.
Swing joint device.

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